I've got news for you, there's already a wall along the border with barbed wire...and then hundreds of miles of desert after that. Nothing but desert. People die trying to cross it. How is another wall going to stop anyone? They already find alternate routes. El Chapo built a tunnel equipped with a motorbike on a track. Face it, you all got scammed. Trump is proof that a sucker is born every minute. Now you get to pay for a wall and deal with all the undocumented immigrants that have already found a way around the wall. Considering Mexico is one of our top trade partners, you can also expect that 20% tariff to be passed on to the customer, us.
This is just willing defeat sanctioned by humanitarianism. There are large open stretches without fence, that's how the Mexicans get across. No one would risk their lives and their families lives to cross the border.
Put up a triangular prism razor wire, put up some machine gun nests, and you'll have a fortified border on par with Israel's.
Better yet stop giving the leeches welfare, free childcare and free education and they'll deport themselves. These are lazy, selfish individuals who will only reside in the US as long as their living conditions are marginally better than in Mexico.